According to the symptoms you describe ("white bump next to the anus hole and it is very uncomfortable whenever I sit or sometimes even walk"), you might be experiencing a peri-anal abscess. Peri-anal abscesses develop from the glands surrounding the anus. These glands may plug in, leading to infection. When they fill with pus, they may burst inward. The pus causes an abscess or pus collection in the spaces around the rectum or anus. The signs of an abscess include pain in the anal area or buttocks, a lump(s) in the anal area, fatigue, and painful bowel movements. You should consult your primary health care doctor for an examination and to seek a diagnosis of the condition.